Agitator with internal twin motor drive system

ABSTRACT

A floor care apparatus includes a housing having a nozzle assembly and a canister assembly. Both a suction generator and a dirt collection vessel are carried on the housing. An agitator cavity is provided on the nozzle assembly. A rotary agitator is provided in the agitator cavity. The rotary agitator includes an internal space. An agitator drive system is provided in the internal space of the rotary agitator. The agitator drive system includes first and second drive motors that simultaneously drive the agitator.

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION

The present invention relates generally to the floor care appliance field and, more particularly, to a vacuum cleaner incorporating an agitator with an internal twin motor drive system.

BACKGROUND OF THE INVENTION

A vacuum cleaner, equipped with a rotary agitator having a single internal drive motor, is disclosed in U.S. Pat. No. 7,070,636. This patent is owned by the assignee of the present invention.

By providing an agitator with an internal drive motor, one eliminates the need for a drive belt along with the inconvenient and troublesome maintenance required by such a feature. This represents a significant benefit. In addition, the overall design of the drive system is compact. Further, the internal drive system has proven to be a reliable performer characterized by a long service life.

Despite these numerous benefits and advantages, further improvements are possible. The present invention relates to an agitator with an internal twin motor drive system. Such an arrangement provides a number of additional advantages over the state of the art agitator equipped with a single internal drive motor.

Specifically, the internal twin motor drive system allows one to provide an agitator of reduced diameter with the same level or even more torque as provided by the state of the art single internal motor design. Thus, the vacuum cleaner equipped with the new internal twin motor drive system may be made with a lower profile. This allows for cleaning under lower bathroom and kitchen cabinet overhangs and furniture. Further, the twin motors may be positioned in the agitator to better balance the weight over the agitator and the overall vacuum cleaner. This functions to increase the cleaning performance and overall service life of the vacuum cleaner while providing the vacuum cleaner with neutral handling characteristics so that it is easier to steer.

SUMMARY OF THE INVENTION

To achieve the foregoing and other objects, and in accordance with the purposes of the present invention as described herein, an improved floor care apparatus is provided. That floor care apparatus comprises a housing including a nozzle assembly and a canister assembly, a suction generator carried on the housing, and a dirt collection vessel carried on the housing. An agitator cavity is provided on the nozzle assembly. A rotary agitator is provided in the agitator cavity. The rotary agitator includes an internal space. An agitator drive system is provided in the internal space of the rotary agitator. That agitator drive system includes a first drive motor and a second drive motor.

More specifically, the first and second drive motors are aligned within the internal space. The first drive motor is provided adjacent the first end of the rotary agitator while the second drive motor is provided adjacent a second end of the rotary agitator in order to provide weight balance. An air intake opening is provided at each end of the rotary agitator. An air exhaust outlet is provided between the first and second drive motors. Air filters are provided in the internal space between the intake openings and the drive motors and cooling air is drawn into these filters through the intake opening by the first and second drive motors. The cooling air flows through the first and second drive motors before being exhausted from the rotary agitator through the exhaust outlet.

In accordance with an additional aspect of the present invention, a method is provided for driving a rotary agitator in a vacuum cleaner. The method comprises providing a first agitator drive motor, providing a second agitator drive motor and simultaneously driving the rotary agitator with the first and second agitator drive motors.

More specifically, the method includes mounting both the first and second agitator drive motors in an internal space within the rotary agitator. Further, the method includes aligning the first and second agitator drive motors within the internal space while also orienting the first and second agitator drive motors in opposite directions. Thus, the method includes driving the first agitator drive motor in a clockwise direction while simultaneously driving the second agitator drive motor in a counter-clockwise direction.

Still further, the method includes the step of reducing the overall diameter of the rotary agitator. This is done by using first and second agitator drive motors to drive the rotary agitator instead of a single drive motor where the single drive motor has a diameter D and power output P while each of the first and second agitator drive motors has a diameter less than D and a combined power output of at least P. Thus, the resulting agitator has a reduced diameter allowing the vacuum cleaner or floor care appliance to have a lower overall profile so as to better reach under cabinet overhangs, furniture and the like. At the same time, vacuum cleaner or floor care appliance performance is in no way compromised.

In the following description there is shown and described several different embodiments of the invention, simply by way of illustration of some of the modes best suited to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated herein and forming a part of the specification, illustrate several aspects of the present invention and together with the description serve to explain certain principles of the invention. In the drawings:

FIG. 1 is a perspective view of a vacuum cleaner constructed in accordance with the teachings of the present invention;

FIG. 1 a is a schematical diagram of the vacuum cleaner illustrated in FIG. 1;

FIG. 2 is a cross-sectional view through the nozzle assembly of the vacuum cleaner showing the agitator and the agitator drive system;

FIG. 2 a is a detailed transverse cross-sectional view through the agitator illustrating the first power transmission assembly received in the internal space of the agitator;

FIG. 2 b is a detailed cross sectional view of the first end of the agitator including the first drive motor and first transmission assembly; and

FIG. 3 is an exploded perspective view of the agitator and the agitator drive system.

Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

Reference is now made to FIGS. 1 and 1 a showing the floor care appliance 10 of the present invention. It should be appreciated that while the floor care appliance 10 is illustrated as an upright vacuum cleaner, embodiments of the present invention also include canister vacuum cleaners, extractors and the like incorporating the rotary agitator and agitator drive system 12 of the present invention as described in detail below.

The upright vacuum cleaner 10 illustrated includes a housing 11 having a nozzle assembly 14 and a canister assembly 16. The canister assembly 16 further includes a control handle 18 and a hand grip 20. The hand grip 20 carries a control switch 22 for turning the vacuum cleaner 10 on and off. Of course, electrical power is supplied to the vacuum cleaner 10 from a standard electrical wall outlet through a cord (not shown).

At the lower portion of the canister assembly 16, rear wheels (not shown) are provided to support the weight of the vacuum cleaner 10. A second set of wheels on the nozzle assembly 14 (also not shown) allow the operator to raise and lower the nozzle assembly through selective manipulation of the height adjustment switch 24. Such a height adjustment mechanism is well known in the art. To allow for convenient storage of the vacuum cleaner 10, a foot latch 26 functions to lock the canister assembly 16 in an upright position as illustrated in FIG. 1. When the foot latch 26 is released, the canister assembly 16 may be pivoted relative to the nozzle assembly 14 as the vacuum cleaner 10 is manipulated to-and-fro to clean the floor.

The canister assembly 16 includes a cavity 28 adapted to receive and hold the dirt collection vessel 30. In the illustrated embodiment, the cavity 28 comprises a filter bag compartment that is accessed through a removable door 32. A dirt collection vessel in the form of a replaceable filter bag 30 is received and held in that cavity. In alternative embodiments of the present invention the cavity 28 receives a dirt cup. Substantially any design of dirt cup known in the art may be provided including those designed to provide cyclonic air flow. As also known in the art, such a dirt cup may or may not include a main filter assembly.

In the illustrated embodiment, the housing 11 and, more particularly, the canister assembly 16 also carries a suction generator 36. Such a suction generator 36 comprises a suction fan and cooperating drive motor that function to generate a vacuum air stream for drawing dirt and debris from the surface to be cleaned. While the suction generator 36 is illustrated as being carried on the canister housing 16, it should be appreciated that it could likewise be carried on the nozzle assembly 14 if desired.

The nozzle assembly 14 includes an agitator cavity 38 that houses a rotary agitator 40. As best illustrated in FIG. 2, the rotary agitator 40 incorporates an outer cylindrical wall 42 that holds a series of bristle tufts 44 that project outwardly. The cylindrical wall 42 also defines an internal space 44 that receives an agitator drive system 46 that will be described in greater detail below. The wall 42 of the agitator 40 may be made from, for example, metal, wood, ceramic, plastic and composite materials. More specifically, such materials include but are not limited to aluminum, steel, pressed wood and fiberglass reinforced plastics.

During operation, the scrubbing action of the bristle tufts 44 on the agitator 40 and the negative air pressure created by the suction generator 36 cooperate to brush and beat dirt and debris from the nap of a carpet being cleaned and then draw dirt and debris laden air from the agitator cavity and suction inlet 38 into the dirt collection vessel 30. Specifically, the dirt and dust-laden air passes serially through the suction inlet 38 and hose and/or integrally molded conduit in the nozzle assembly 14 and/or canister assembly 16 as is known in the art. Next, it is delivered into the dirt collection vessel/filter bag 30 which serves to trap the suspended dirt, dust and other particles inside while allowing the now clean air to pass freely through to the suction generator 36. A secondary filter (not shown) may be provided between the dirt collection vessel/filter bag 30 and the suction generator 36 in order to further insure that no particulates are ingested by the motor of the suction generator. After the air stream passes over the motor of the suction generator 36 to provide cooling, it is forced through a final filtration cartridge 48 before being returned to the environment through an exhaust port 34.

As best illustrated in FIG. 2, the agitator drive system includes a first drive motor 52 and a second drive motor 54. The two drive motors 52, 54 are aligned along the longitudinal axis A of the agitator 40 within the internal space 46. The first and second agitator drive motors 52, 54 are also oriented in opposite directions. Specifically, the first drive motor 52 is received and held on a first motor support 56 while the second drive motor 54 is received and held on a second motor support 58. The first motor support 56 includes a mounting block 60 keyed into a slot 62 in one side of the nozzle assembly 14 while the second motor support 58 includes a mounting block 64 that is keyed into a slot 66 at the opposite side of the nozzle assembly (see also detailed showing in FIG. 2 b). A first bearing assembly 68 is carried on the first motor support 56 and provided between the first motor support and the first end of the rotary agitator 40. Similarly, a second bearing assembly 70 is provided on the second motor support 58 and received between the second motor support and a second end of the agitator 40. The two bearing assemblies 68, 70 support the agitator 40 in the agitator cavity 38 of the nozzle assembly 14 while allowing the agitator to freely rotate relative to the nozzle assembly.

As further illustrated in FIGS. 2 and 3, the first drive motor 52 includes a first drive shaft 72 and with first gear teeth 74 while the second drive motor 54 includes a second drive shaft 76 with second gear teeth 78. A first power transmission assembly, generally designated by reference numeral 80 is received in the internal space 46 and transmits power from the first drive motor 52 to the rotary agitator 40. Similarly, a second transmission assembly 82 is received in the internal space 46 and transmits power from the second drive motor 54 to the rotary agitator 40.

Reference is now made to FIGS. 2, 2 a, 2 b and 3 so as to allow detailed description of the first transmission assembly 80. As illustrated, the first transmission 80 includes a first planetary gear set carrier 84 carrying a first planetary gear set comprising three gears 86, a first drive ring 88 and an associated rubber drive boot 90. The first drive motor 52 drives the first drive shaft 72. The drive shaft 72 extends through a bearing 92 held in the hub 94 of the planetary gear set carrier 84. The planetary gear set carrier 84 includes three stub shafts 96 that support each of the planetary gears 86. Each of the planetary gears 86 include teeth that mesh with the gear teeth 74 on the drive shaft 72. Additionally, the planetary gears 86 mesh with the teeth of an annular gear 98 that is fixed to the housing of the first drive motor 52 by pin or other means. Thus, it should be appreciated that as the drive shaft 72 is driven by the first drive motor 52, the planetary gears 86 are driven around the annular gear 98, thereby causing the planetary gear set carrier 84 to rotate.

As noted above, planetary gear set carrier 84 also includes the drive ring 88 and the associated rubber drive boot 90. The drive ring 88 and rubber drive boot 90 both include a series of spaced channels 100 that receive and engage axial ribs 102 projecting inwardly radially from the inner surface of the cylindrical wall 42 of the rotary agitator 40. Thus, the rotation of the planetary gear set carrier 84 is transmitted by the drive ring 88 and associated drive boot 90 directly to and causes like rotation of the agitator 40. The rubber drive boot 90 provides the necessary damping to ensure the smooth transmission of power to the agitator 40.

The second transmission assembly 82 that transmits power from the second drive motor 54 to the agitator 40 is substantially identical to the first transmission assembly 80 and like reference numbers have been utilized to identify corresponding parts of the second transmission assembly in the drawing figures. Here it should be noted that the first drive motor 52 and first transmission assembly 80 are oriented in a first direction within the internal space 46 while the second drive motor 54 and second transmission assembly 82 are oriented in the opposite direction so that the two appear to be mirror images. Both drive motors 52, 54 simultaneously drive the rotary agitator 40 through their respective transmission assemblies 80, 82. To achieve this end the first agitator drive motor 52 is operated in a counter-clockwise direction while the second agitator drive motor 54 is operated in a clockwise direction.

It is important to provide proper cooling to the first and second drive motors 52, 54 confined within the internal space 46 in the rotary agitator 40. Toward this end, a first intake opening 110 is provided at a first end of the agitator 40 and a second intake opening 112 is provided at a second end of the agitator. A first air filter 114 is provided in the internal space 46 between the first intake opening 110 and the first drive motor 52. Similarly, a second air filter 116 is provided in the internal space 46 between the second intake opening 112 and the second drive motor 54.

A third filter 118 is provided in the internal space 46 between the first and second drive motors 52, 54. The third filter 118 covers a series of air exhaust outlets 120 provided in the wall 42 of the agitator 40. Typically the filters 114, 116 and 118 are made from open cell foam, woven filter media or non-woven filter media.

Air is drawn into the air intake openings 110, 112 and then through the first and second air filters 114, 116 by operation of the first and second drive motors 52, 54. The air is then forced past both transmission assemblies 80, 82 and the third filter 118 before being exhausted from the rotary agitator 40 through the exhaust outlets 120 (note action arrows B in FIGS. 2 and 2 b).

Advantageously, by using an agitator drive system 12 incorporating dual drive motors 52, 54, it is possible to reduce the overall diameter of the agitator 40 as well as the overall height of the nozzle assembly 14. The resulting “low profile” nozzle assembly 14 is capable of more easily fitting under vacuum cleaning obstacles such as furniture and bathroom and kitchen cabinets that overhand the floor so as to allow more complete and convenient cleaning. Further, this is accomplished without any loss of power P. More specifically, the overall diameter of the rotary agitator 40 is reduced by using first and second agitator drive motors 52, 54 to drive the rotary agitator instead of a single drive motor where the single drive motor has a diameter D and a power output (torque) P while each of the first and second agitator drive motors 52, 54 has a diameter less than D and a combined power output of at least P. For example, a state of the art vacuum cleaner uses a single internal agitator drive motor to drive the rotary agitator. That single agitator drive motor has a diameter of 46 mm requiring an agitator with an outer diameter of 56 mm. In contrast, the rotary agitator 40 of the present invention equipped with the internal dual motor drive system 12 has an overall diameter of 46 mm: that is 10 mm less than the old rotary agitator which is almost an 18% reduction in diameter. This is possible as the dual drive motors 52, 54 each have an outer diameter of only 39 mm. Specifically, since two drive motors 52, 54 are used instead of one; the drive motors themselves may be smaller thereby allowing one to produce a nozzle assembly 14 with a lower overall profile. Advantageously, this is accomplished without any loss of power.

The foregoing description of the preferred embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. The drawings and preferred embodiments do not and are not intended to limit the ordinary meaning of the claims in their fair and broad interpretation in any way. 

1. A floor care apparatus, comprising: a housing including a nozzle assembly and a canister assembly; a suction generator carried on said housing; a dirt collection vessel carried on said housing; an agitator cavity provided on said nozzle assembly; a rotary agitator provided in said agitator cavity, said rotary agitator including an internal space; and an agitator drive system provided in said internal space of said rotary agitator, said agitator drive system including a first drive motor and a second drive motor.
 2. The apparatus of claim 1, wherein said first and second drive motors are aligned within said internal space.
 3. The apparatus of claim 2, wherein said first drive motor is provided adjacent a first end of said rotary agitator and said second drive motor is provided adjacent a second end of said rotary agitator so as to provide weight balance.
 4. The apparatus of claim 3, further including a first intake opening at a first end of said agitator, a second intake opening at a second end of said agitator and an exhaust outlet in a wall of said rotary agitator between said first drive motor and said second drive motor.
 5. The apparatus of claim 4, further including a first air filter in said internal space between said first drive motor and said first intake opening, a second air filter in said internal space between said second drive motor and said second intake opening and a third air filter in said internal space between said first and second drive motors and covering said exhaust outlet; cooling air being drawn into said filter through said first and second air intake openings by said first and second drive motors, said cooling air flowing through said first and second drive motors before being exhausted from said rotary agitator through said exhaust outlet.
 6. The apparatus of claim 5, further including a first motor support engaging said first motor and mounting said first motor to said nozzle assembly and a second motor support engaging said second motor and mounting said second motor to said nozzle assembly.
 7. The apparatus of claim 6, further including a first bearing assembly provided between said first motor support and said first end of said rotary agitator and a second bearing assembly provided between said second motor support and said second end of said rotary agitator.
 8. The apparatus of claim 7, further including a first power transmission assembly received in said internal space and transmitting power from said first drive motor to said rotary agitator and a second power transmission assembly received in said internal space and transmitting power from said second drive motor to said rotary agitator.
 9. The apparatus of claim 8, wherein said first drive motor includes a first drive shaft and said second drive motor includes a second drive shaft.
 10. The apparatus of claim 9, wherein said first power transmission assembly includes a first planetary gear set carrier carrying a first planetary gear set as well as a first drive ring and associated rubber drive boot.
 11. The apparatus of claim 10, wherein said second power transmission assembly includes a second planetary gear set carrier carrying a second planetary gear set as well as a second drive ring and associated rubber drive boot.
 12. The apparatus of claim 11, wherein said first planetary gear set carrier holds a first bearing and said first drive shaft extends through said first bearing while said second planetary gear set carrier holds a second bearing and said second drive shaft extends through said second bearing.
 13. The apparatus of claim 12, further including a first annular gear fixed to a first housing of said first drive motor and a second annular gear fixed to a second housing of said second drive motor, said first planetary gear set being driven around said first annular gear by said first drive motor while said second planetary gear set is being drive around said second annular gear by said second drive motor.
 14. The apparatus of claim 13, further including a plurality of axial ribs projecting inwardly into said internal space from said wall of said rotary agitator.
 15. The apparatus of claim 14, wherein said first and second drive ring and associated rubber drive boot include a plurality of spaced channels that receive and engage said plurality of axial ribs on said wall of said rotary agitator so that said rotary agitator is rotated with said first and second planetary gear set carriers.
 16. A method of driving a rotary agitator in a vacuum cleaner comprising: providing a first agitator drive motor; providing a second agitator drive motor; and simultaneously driving said rotary agitator with said first agitator drive motor and said second agitator drive motor.
 17. The method of claim 16, including mounting both of said first and second agitator drive motors in an internal space within said rotary agitator.
 18. The method of claim 17, including aligning said first and second agitator drive motors within said internal space in said rotary agitator while also orienting said first and second agitator drive motors in opposite directions.
 19. The method of claim 18, including driving said first agitator drive motor in a counter-clockwise direction while simultaneously driving said second agitator drive motor in a clockwise direction.
 20. The method of claim 19, including reducing the overall diameter of said rotary agitator by using said first and second agitator drive motors to drive said rotary agitator instead of a single drive motor where said single drive motor has a diameter D and a power output of P while each of said first and second agitator drive motors has a diameter less than D and a combined power output of at least P. 